Agricultural machine

ABSTRACT

An agricultural machine includes a body, a connecting mechanism, an operating device for pivoting the connecting mechanism into at least two working positions, transmission elements which include at least one gearbox, and a control mechanism intended to pivot the gearbox into operating positions corresponding to the working positions of the connecting mechanism. In accordance with the invention, the control mechanism is installed, among others, between the gearbox and the operating device. This control mechanism can also include a first control cylinder installed between the connecting mechanism and the body and connected in series to a second control cylinder installed between the body and the gearbox.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention regards an agricultural machine comprising:

a body equipped with at least one working component;

a connecting mechanism allowing connection of said agricultural machineto a tractor, said connecting mechanism being connected to said body bya first joint with an upwardly directed axis;

an operating device for pivoting the connecting mechanism with respectto said body around the axis of said first joint, said connectingmechanism being positionable in at least two working positions;

transmission elements for powering said at least one working component,said transmission elements comprising at least one gearbox connected tothe body by a second joint with an upwardly directed axis; and

a control mechanism for pivoting said gearbox with respect to the bodyaround the axis of said second joint wherein the gearbox is positionablein operating positions that correspond to said working positions of theconnecting mechanism.

2. Discussion of the Background

An agricultural machine is described in document EP 0 277 343 A1 andcomprises a mower-conditioner. First, this known machine comprises abody that consists of a chassis that moves over the ground via twowheels, and a harvesting device suspended in the chassis by means of adrawn deformable quadrilateral suspension device. This known machinealso includes a drawbar allowing it to be connected to a tractor. Thisdrawbar is connected to the midsection of the chassis by means of ajoint whose axis is roughly vertical so that it can occupy at least twoworking positions by pivoting around said axis. The harvesting deviceitself comprises a carrying structure carrying cutting drums and aconditioning rotor installed behind them.

This known machine additionally comprises transmission elements designedto power the cutting drums and the conditioning rotor. Thesetransmission elements consist primarily of a transmission deviceinstalled in the front part of the drawbar that is designed to receivethe movement from the power take-off shaft of the tractor via a firsttelescopic transmission shaft with universal joints. These transmissionelements also consist of a gearbox connected to the carrying structureof the harvesting mechanism by means of a joint whose axis is roughlyparallel to the axis of the joint connecting the drawbar to the chassis.This gearbox receives the movement of the transmission device outputshaft via a second telescopic transmission shaft with universal joints.The output shaft of the gearbox transmits the movement to the drivecomponents of the harvesting device.

The axis of the joint connecting the gearbox to the carrying structureof the harvesting mechanism is located in the vertical plane pointing inthe direction of displacement and enclosing the axis of the jointconnecting the drawbar to the chassis, and is located in front of thislatter axis. As a result, it is possible to swivel said gearbox aroundthe axis of its joint when the drawbar is pivoted into its variouspositions so that the input shaft of the gearbox is always pointingtowards the front of the drawbar. To this end, this known machinecomprises a control mechanism that consists of a coupling. This couplingcomprises a first forked coupling that is guided in rotation between thetwo universal joints of the second telescopic transmission shaft and asecond forked coupling mounted on the gearbox and inside which the inputshaft of said gearbox is guided in rotation. These two forked couplingsare connected to each other by a joint with an approximately horizontalaxis that passes through the center of the universal joint of the secondtelescopic transmission shaft located beside the input shaft of thegearbox.

In this known machine, the position of the gearbox is controlled via thesecond telescopic transmission shaft in response of the swiveling of thedrawbar. Additionally, the joint connecting the two forked couplingsenables the harvesting mechanism to move with respect to the chassis inorder to adjust to the ground terrain.

The control mechanism used on this known machine has severaldisadvantages. It first requires a special telescopic transmission shaftwith universal joints since the first forked coupling is guided inrotation thereon by means of two bearings. Assembly then requires thatrelatively strict machining tolerances be observed since the axis of thejoint connecting the two forked couplings together must pass preciselythrough the center of the universal joint of the second telescopictransmission shaft located beside the input shaft of the gearbox.

U.S. Pat. No. 5,272,859 presents another mower-conditioner comparable tothe one described in EP 0 277 343 A1. The control mechanism, which isdesigned to pivot the gearbox to position it properly according to theposition of the drawbar, is made up of a telescopic control rod locatedbetween the drawbar and the gearbox. This telescopic control rodcomprises an inner section connected to the drawbar by means of a balland socket joint and capable of sliding inside an outer sectionconnected indirectly to the gearbox. At its end beside the gearbox, theouter section of the telescopic control rod has two lugs between whichextends a rigid tubular housing that is part of the gearbox. Said lugsare connected to the said housing by means of a joint with a roughlyhorizontal axis that passes through the center of the universal joint ofthe second telescopic transmission shaft located next to the gearbox.

In this known machine, the position of the gearbox is controlled via thetelescopic control rod in response of pivoting of the drawbar. Moreover,the fact that the telescopic control rod can lengthen and shortencombined with the pivoting enabled by the joint connecting said rod tothe gearbox allows the harvesting mechanism to move with respect to thechassis in order to adapt itself to the ground.

In order to allow the inner section to slide easily inside the outersection, it is necessary to provide sufficient play between these twosections. Under these conditions, absorption of the driving torqueapplied to the gearbox causes the telescopic control rod to bend. Thiscan slow the shortening of the telescopic control rod during theharvesting mechanism's adjustment to the ground contours. Additionally,the lengthening and shortening of the telescopic control rod under alarge load risks causing relatively rapid wear of said rod.

EP 0 678 237 A1 describes a mower that primarily comprises a bodyconsisting of a chassis that moves over the ground via two wheels and acutting mechanism suspended from the chassis by means of a suspensiondevice that allows the cutting mechanism to move with respect to saidchassis in order to adapt itself to the ground contours. This mower alsohas a drawbar making it possible to connect it to a tractor. Thisdrawbar is connected to the mid-section of the chassis by means of ajoint with an approximately vertical axis so that it can occupy at leasttwo working positions by swiveling around said axis.

This known mower also comprises transmission elements designed to powerthe cutting tools. These transmission elements consist first of all ofan upper gearbox mounted on the drawbar and whose input shaft receivesthe motion of the output shaft of a transmission device installed in thefront part of the drawbar via a telescopic transmission shaft withuniversal joints. The output shaft of this upper gearbox extends in aroughly parallel fashion to the axis of the joint connecting the drawbarto the chassis. This output shaft is coaxial with the input shaft of thelower gearbox, whose output shaft is connected to the drive componentsof the cutting mechanism via another telescopic transmission shaft withuniversal joints.

The lower gearbox is thus borne by the upper gearbox so that it iscapable of swiveling around the common axis of the output shaft of theupper gearbox and the input shaft of the lower gearbox. During pivotingof the drawbar, the position of the lower gearbox is controlled by aguiding mechanism. In a first embodiment, this guiding mechanismconsists of a rod installed between the lower gearbox and the cuttingmechanism, roughly parallel to the transmission shaft connecting theoutput shaft of said lower gearbox to the drive components of thecutting mechanism. In a second embodiment, the guiding mechanismconsists of a deformable parallelogram connected to the chassis.

In this known mower, the position of the lower gearbox is controlled viathe upper gearbox during the swiveling of the drawbar. This solution isrelatively expensive since it requires two gearboxes capable of pivotingwith respect to each other.

SUMMARY OF THE INVENTION

The aim of the present invention is to propose another solution withoutthe disadvantages of the known solutions.

To this end, a first agricultural machine in accordance with theinvention is characterized in that the control mechanism for positioningthe gearbox is installed, among others, between said gearbox and theoperating device for pivoting the connecting mechanism with respect tothe body of the machine.

In this manner, the gearbox is brought into the appropriate operatingposition when the operating device brings the connecting mechanism intoany one of its various working positions.

In this first agricultural machine, in accordance with the invention,the position of the gearbox is not controlled by the connectingmechanism itself, but, among others, by the operating device intended tobring the connecting mechanism into its various working positions.

The invention also regards the characteristics hereinafter consideredseparately or in all their technically possible combinations.

In a first group of embodiments, said control mechanism comprises acable connected between the operating device and the gearbox.

This cable can pass through a sleeve and control the pivoting of thegearbox in one direction only, while the control mechanism will consistin addition of a flexible control component installed between the bodyand the gearbox that controls the pivoting of said gearbox in the otherdirection. In this case, it may advantageously be provided that thereaction generated by the driving torque applied to the gearbox tends tocause said gearbox to pivot in the same direction as the flexiblecontrol component does. It may also be advantageous to provide that theoperating device acts on the cable by means of a flexible element,preferably a compression element.

However, it can also be provided that the cable constitutes a closedloop that passes through two half-sleeves installed on the body. In thiscase, the cable will control the pivoting of the gearbox in bothdirections.

Also, the sleeve or the two half-sleeves may be advantageouslycompressed by a flexible compression element.

When the operating device comprises an operating cylinder positionedbetween the connecting mechanism and the body, the cable can also beconnected advantageously to said cylinder near the joint connecting thecylinder to the body. To this end, the operating cylinder mayadvantageously include an extension that extends beyond the jointconnecting said cylinder to the body and to which the cable will beconnected.

In a second group of embodiments, said control mechanism comprises anarticulated rod assembly. This rod assembly can consist of a leverattached to the body, a first rod installed between the operating deviceand said lever, and a second rod installed between said lever and thegearbox. In this case, said lever may be attached by one of its ends tothe body, said second rod may be attached to the other end of said leverand said first rod may be attached to said lever between its two ends.

When the operating device includes an operating cylinder positionedbetween the connecting mechanism and the body, the rod assembly can beadvantageously connected to said cylinder near the joint connecting thecylinder to the body as well. Said cylinder can then also comprise anextension that extends beyond said joint and to which the rod assemblywill be connected.

A second agricultural machine in accordance with the invention ischaracterized in that the control mechanism for positioning the gearboxcomprises:

a first control cylinder installed between the connecting mechanism andthe body, and

a second control cylinder installed between the body and the gearbox andconnected in series to the first control cylinder.

The invention also regards the characteristics hereinafter consideredseparately or in all their technically possible combinations.

The first control cylinder and the second control cylinder can be of asingle-action type. The second control cylinder will thus control thepivoting of the gearbox in one direction, while the control mechanismwill also comprise a flexible control component installed between thebody and the gearbox that controls the pivoting of said gearbox in theother direction. There too, it will be advantageous that the reactiongenerated by the driving torque applied to the gearbox tends to causesaid gearbox to pivot in the same direction as the flexible controlcomponent does.

When the operating device comprises an operating cylinder positionedbetween the connecting mechanism and the body, this operating cylinderand the first control cylinder can form a unit positioned between theconnecting mechanism and the body. This unit can comprise a cylinderbody equipped with an operating chamber as well as a control chamber,and a rod equipped with an operating piston that extends into theoperating chamber to form with it the operating cylinder, said rodfurther extending into the control chamber to form with it the firstcontrol cylinder.

However, it is, of course, entirely possible that the first controlcylinder and the second control cylinder be of a dual-action type and beconnected in a closed circuit.

When the operating device comprises an operating cylinder positionedbetween the connecting mechanism and the body, this operating cylinderand the first control cylinder can here too form a unit articulatedbetween the connecting mechanism and the body. This unit can comprise acylinder body equipped with an operating chamber and a control chamber,and a rod equipped with an operating piston that extends into theoperating chamber to form with it the operating cylinder, said rodfurther comprising a control piston extending into the control chamberto form with it the first control cylinder.

In each of these two agricultural machines, according to the invention,it can be provided that the gearbox occupies two operating positions,each defined by a respective stop device installed on the body.

Finally, the invention also regards the following characteristicsconsidered in all their technically possible combinations with theprevious characteristics:

the operating cylinder is a dual-action cylinder;

the transmission elements comprise at least one telescopic transmissionshaft with universal joints connected to the input shaft of the gearbox;

said at least one transmission shaft or at least one of saidtransmission shafts is supported by the connecting mechanism;

the transmission elements receive the movement of the power take-offshaft of the tractor vehicle to which the agricultural machine isintended to be connected;

the body rests on the ground by means of at least one wheel, and theconnecting mechanism consists of a drawbar connected to the midsectionof said body;

the body comprises a chassis to which the connecting mechanism isconnected and in which is (are) suspended the working component(s) bymeans of a suspension device that makes it possible for it (them) tomove with respect to the chassis in order to adapt to the groundterrain.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the presentinvention will be more fully appreciated as the same becomes betterunderstood from the following detailed description when considered inconnection with the accompanying drawings in which like referencecharacters designate like or corresponding parts throughout the severalviews and wherein:

FIG. 1 shows a top view of an agricultural machine according to theinvention;

FIG. 2 shows the control mechanism for positioning the gearbox of theagricultural machine in the left mowing position;

FIG. 3 shows said control mechanism in the right mowing position;

FIG. 4 shows a second embodiment of said control mechanism in the leftmowing position;

FIG. 5 shows the control mechanism seen in FIG. 4 in the right mowingposition;

FIG. 6 shows a third embodiment of said control mechanism in the leftmowing position;

FIG. 7 shows the control mechanism of FIG. 6 in the right mowingposition;

FIG. 8 shows a fourth embodiment of said control mechanism in the leftmowing position;

FIG. 9 shows the control mechanism of FIG. 8 in the right mowingposition;

FIG. 10 shows a fifth embodiment of said control mechanism in the leftmowing position; and

FIG. 11 shows the control mechanism of FIG. 10 in the right mowingposition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 3 show an agricultural machine, according to the invention,embodied in the form of a mower-conditioner 1. It is hitched to atractor (not shown) which, during use, pulls it in a forward direction2.

In the description, the following notions "forward", "rearward", "infront of" and "behind" are defined with respect to this forwarddirection 20 The notions "right" and "left" are defined by looking atthe mower-conditioner 1 from behind in the forward direction 2.

This mower-conditioner consists of a body 3 that moves along the groundvia two wheels 4, and a drawbar 5 intended to be connected at its frontend to said tractor in a manner known to a person skilled in the art.Moreover, said drawbar 5 is connected at its rear end to the body 3 bymeans of a joint 6 with a geometrical axis 7 pointing upward (in theexample shown, this geometrical axis 7 is roughly vertical and extendsroughly in the vertical median plane 8 of the body 3 which is orientedin the direction of forward movement 2.) The angular position of thedrawbar 5 with respect to the body 3 can be modified by causing thedrawbar 5 to pivot around the geometric axis 7 of the joint 6. Puttingthe drawbar 5 into the desired angular position and holding the drawbar5 in the latter are achieved by a hydraulic operating cylinder 9 locatedbetween the drawbar 5 and the body 3. As a result of this arrangement,the body 3 of the mower-conditioner 1 can, particularly during work,extend to the left (FIGS. 1 and 2) or to the right (FIG. 3) of thetractor. This enables mowing in both directions of travel.

The body 3 of the mower-conditioner 1 firstly comprises a chassis 10that rests on the ground by means of two wheels 4 which each extend nearone respective outer end of said chassis 10. The body 3 of themower-conditioner 1 also comprises a harvesting mechanism 11 equippedwith cutting components 12 and processing components 13 for the productcut by the cutting components 12 (in the example shown, the cuttingcomponents 12 consist of rotating disks, and the processing components13 consist of a pair of counterrotating conditioning rollers; such disksand conditioning rollers being known to a person skilled in the art).This harvesting mechanism 11 is connected to the chassis 10 by means ofa suspension device 14 consisting in the example shown of threesuspension rods 15, 16, 17: two lower suspension rods 15, 16 and oneupper suspension rod 17. These three suspension rods 15, 16, 17 form adeformable quadrilateral with the chassis 10 and the harvestingmechanism 11 that allows the harvesting mechanism 11 to move essentiallyup and down with respect to the chassis 10 in order to adapt itself tothe ground terrain independently of said chassis 10.

The harvesting mechanism 11 is powered, for example, by means of thepower take-off shaft of the tractor vehicle in a manner known to aperson skilled in the art. The movement thus arrives via a shaft 18supported by the drawbar 5 and is transmitted to a gearbox 19 by atelescopic transmission shaft 20 with universal joints installed betweensaid shaft 18 and the input shaft 21 of the gearbox 19. This gearbox 19is connected to the harvesting mechanism 11 and transmits the movementto the drive components of the cutting components 12 and the processingcomponents 13, not shown, but within the understanding of one skilled inthe art.

The gearbox 19 is connected to the harvesting mechanism 11 by means of ajoint 22 whose geometric axis 23 points upward (in the example shown,this axis 23 is roughly parallel to the axis 7 and extends in front ofthis axis 7; moreover, it extends slightly to the left of the medianvertical plane 8). Thanks to this joint 22, the input shaft 21 of thegearbox 19 is always oriented toward the front end of the drawbar 5regardless of the angular position of this drawbar 5. Positioning andmaintenance of the gearbox 19 in the appropriate angular position areaccomplished by a control mechanism 24.

This control mechanism 24 firstly comprises a cable 25 connected betweenthe operating cylinder 9 and the gearbox 19. To this end, the rod 26 ofthe operating cylinder 9 comprises an extension 27 that extends beyondthe joint 28 connecting the operating cylinder 9 to the chassis 10 ofthe body 3. Said cable 25 also passes through a sleeve 29 that extendsbetween two stop devices 30, 31 and is compressed by a flexible element32. In the example shown, one of these stop devices 30, 31 is part ofthe chassis 10, while the other stop device 31 is part of the harvestingmechanism 11.

This control mechanism 24 also comprises a flexible control component 33located between the harvesting mechanism 11 and the gearbox 19. In theexample shown, this flexible control component 33 consists of a drawspring.

Finally, the gearbox 19 also comprises two lugs 34, 35 that are designedto come into contact with the respective faces 36, 37 of a stop device38. Each of these faces 36,37 of the stop device 38 thus constitutes astop.

Positioning the gearbox 19 into the appropriate operating position isaccomplished in the following manner.

To move from the mowing position on the left of the tractor vehicle(FIGS. 1 and 2) to the mowing position on the right (FIG. 3) oneshortens the operating cylinder 9 to make the drawbar 5 pivot in onedirection 39 around the geometric axis 7 from working position 5G intoworking position 5D. By so doing, the extension 27 of the operatingcylinder 9 pulls the cable 25 and causes the gearbox 19 to pivot in thesame direction 39 around the geometric axis 23. When the drawbar 5reaches its working position 5D, the lug 35 of the gearbox 19 is incontact with the face 37 of the stop device 38. The flexible element 32allows the lug 35 to be in contact with the stop device 38 when thedrawbar 5 reaches its position 5D. In parallel fashion, pivoting thegearbox 19 in this direction 39 stresses the flexible control component33, which thereby accumulates energy.

To move from the mowing position on the right of the tractor vehicle(FIG. 3) to the mowing position on the left (FIGS. 1 and 2), onelengthens the operating cylinder 9 to cause the drawbar 5 to pivot inthe other direction 40 around the geometric axis 7 from working position5D into working position 5G. In so doing, the extension 27 of theoperating cylinder 9 no longer pulls on the cable 25, and it is theflexible control component 33 that will cause the gearbox 19 to pivot inthe same direction 40 around the geometric axis 23. When the drawbar 5reaches its working position 5G, the lug 34 of the gearbox 19 is incontact with the face 36 of the stop device 38, and it is kept in thisposition by the flexible control component 33. In parallel fashion, thereaction generated by the driving torque applied to the gearbox 19 alsotends to cause the gearbox 19 to pivot in this direction 40 and thusassists the flexible control component 33 in keeping the lug 34 of thegearbox 19 in contact with the face 36 of the stop device 38.

The embodiments shown in FIGS. 4 to 11 comprise a certain number ofelements that have been previously described. These elements willconsequently retain the same reference numbers and will not be describedagain. They also comprise a certain number of elements that arecomparable to elements in the mower-conditioner of the precedingexample. These elements will be indicated by the same reference numberas these comparable elements of the preceding example increased by onehundred (FIGS. 4 and 5), by two hundred (FIGS. 6 and 7), by threehundred (FIGS. 8 and 9) and by four hundred (FIGS. 10 and 11).

FIGS. 4 and 5 show a second embodiment of a control mechanism 124equipping an agricultural machine 101. This mechanism comprises a singlecable 125 constituting a closed loop that is connected to the operatingcylinder 9 and to the gearbox 119. This cable 125 passes through twohalf-sleeves 129A, 129B each extending between two stops 130A, 131A,130B, 131B and each compressed by a respective flexible element 132A,132B. Stops 130A, 130B are part of the chassis 110 of the body 103,while the other stops 131A, 131B are part of the harvesting mechanism111 of said body 103.

Positioning the gearbox 119 into the appropriate operating position isaccomplished in the following manner.

To move from the mowing position on the left of the tractor vehicle(FIG. 4) to the mowing position on the right (FIG. 5), one shortens theoperating cylinder 9 to cause the drawbar 5 to pivot in the direction 39around the geometric axis 7 from working position 5G into workingposition 5D. In so doing, the extension 27 of the operating cylinder 9pulls on the cable 125 toward the right causing the gearbox 119 to turnin the same direction 39 around the geometric axis 23. When the drawbar5 reaches its working position 5D, the lug 35 of the gearbox 119 is incontact with the face 37 of the stop device 38. These flexible elements132A, 132B allow the lug 35 to be in contact with the stop device 38when the drawbar 5 reaches its position 5D.

To move from the mowing position on the right of the tractor vehicle(FIG. 5) to the mowing position on the left (FIG. 4), one extends theoperating cylinder 9 in order to cause the drawbar 5 to pivot in thedirection 40 around the geometric axis 7 from working position 5D intoworking position 5G. In so doing, the extension 27 of the operatingcylinder 9 pulls the cable 125 toward the left causing the gearbox 119to pivot in the same direction 40 around the geometric axis 23. When thedrawbar 5 reaches its working position 5G, the lug 34 of the gearbox 119is in contact with the face 36 of the stop device 38. Here, as well, theflexible elements 132A, 132B allow the lug 34 to be in contact with thestop device 38 when the drawbar 5 reaches its position 5G.

FIGS. 6 and 7 show a third embodiment of a control mechanism 224equipping an agricultural machine 201. This consists of an articulatedrod assembly that comprises a lever 41 and two rods 42, 43. In thisembodiment, the lever 41 is connected at its rear end to the chassis 210of the body 203 by means of a joint 44. The first rod 42 is positionedbetween the extension 27 of the rod 26 of the operating cylinder 9 andthe middle part of said lever 41. Finally, the second rod 43 ispositioned between the front end of the lever 41 and the rear portion ofthe gearbox 219.

Positioning the gearbox 219 into the appropriate operating position isaccomplished in the following manner.

To move from the mowing position on the left of the tractor (FIG. 6) tothe mowing position on the right (FIG. 7), one shortens the operatingcylinder 9 in order to cause the drawbar 5 to pivot in the direction 39around the geometric axis 7 from working position 5G into workingposition 5D. In so doing, the extension 27 of the operating cylinder 9pulls on the first rod 42 and makes the lever 41 pivot to the right.When it pivots to the right, the lever 41 pushes on the second rod 43causing the gearbox 219 to pivot in the same direction 39 around thegeometric axis 23. When the drawbar 5 has reached its working position5D, the gearbox 219 is also located in its appropriate operatingposition.

To move from the mowing position on the right of the tractor (FIG. 7) tothe mowing position on the left (FIG. 6), one extends the operatingcylinder 9 in order to cause the drawbar 5 to pivot in the direction 40around the geometric axis 7 from working position 5D into workingposition 5G. In so doing, the extension 27 of the operating cylinder 9pushes on the first rod 42 and causes the lever 41 to pivot to the left.When it pivots to the left, the lever 41 pulls on the second rod 43causing the gearbox 219 to pivot in the same direction 40 around thegeometric axis 23.

FIGS. 8 and 9 show a fourth embodiment of a control mechanism 324equipping an agricultural machine 301. This mechanism comprises a firstcontrol cylinder 45 and a second control cylinder 46 connected in seriesby means of a conduit 47. In this embodiment, this first controlcylinder 45 and this second control cylinder 46 are of the single-actiontype.

The first control cylinder 45 and the operating cylinder 309 form a unit48 positioned between the drawbar 5 and the chassis 310 of the body 303.This unit 48 comprises a cylinder body 49 with an operating chamber 50and a control chamber 51. In addition, this unit 48 comprises a rod 326attached to the chassis 310 by its outside end and whose inside end isdesigned to extend into the control chamber 51 to form with it the firstcontrol cylinder 45. In its midsection, said rod 326 also comprises anoperating piston 52 that extends into the operating chamber 50 in orderto form the operating cylinder 309 with it.

The second control cylinder 46 is positioned between the harvestingmechanism 311 and the gearbox 19.

Finally, the control mechanism 324 also comprises a flexible controlcomponent 33 installed between the harvesting mechanism 311 and thegearbox 19.

Positioning the gearbox 19 into the appropriate operating position isaccomplished in the following manner.

To move from the mowing position on the left of the tractor (FIG. 8) tothe mowing position on the right (FIG. 9), one shortens the operatingcylinder 309 by injecting fluid through the conduit 53 to cause thedrawbar 5 to pivot in the direction 39 around the geometric axis 7 fromworking position 5G into working position 5D. In so doing, the insideend of the rod 326 plunges more and more deeply into the control chamber51 and expels the fluid contained therein into the second controlcylinder 46 through the conduit 47. As a result, the second controlcylinder 46 extends and causes the gearbox 19 to pivot in the samedirection 39 around the geometric axis 23. When the drawbar 5 reachesits working position 5D, the lug 35 of the gearbox 19 is in contact withthe face 37 of the stop device 38. In parallel fashion, pivoting thegearbox 19 in the direction 39 stresses the flexible control component33, which thereby accumulates energy.

To move from the mowing position on the right of the tractor vehicle(FIG. 9) to the mowing position on the left (FIG. 8), one extends theoperating cylinder 309 by injecting fluid via the conduit 54 to causethe drawbar 5 to pivot in the direction 40 around the geometric axis 7from working position 5D into working position 5G. In so doing, theinside end of the rod 326 withdraws progressively from the controlchamber 51 and aspirates the fluid contained in the second controlcylinder 46. The gearbox 19 then pivots in the same direction 40 aroundthe geometric axis 23 under the combined effect of the shortening of thesecond control cylinder 46 and of the flexible control component 33.When the drawbar 5 reaches its working position 5G, the lug 34 of thegearbox 19 is in contact with the face 36 of the stop device 38.

In parallel fashion, it is also provided that the reaction generated bythe driving torque applied to the gearbox 19 tends to cause the gearbox19 to pivot in the direction 40.

FIGS. 10 and 11 show a fifth embodiment of a control mechanism 424equipping an agricultural machine 401. This mechanism comprises a firstcontrol cylinder 445 and a second control cylinder 446 connected in aclosed circuit by means of two conduits 47, 55. In this embodiment, thefirst control cylinder 445 and the second control cylinder 446 are ofthe dual-action type.

Here, too, the first control cylinder 445 and the operating cylinder 309form a unit 448 positioned between the drawbar 5 and the chassis 310 ofthe body 403. This unit 448 comprises a cylinder body 449 with anoperating chamber 50 and a control chamber 451. This unit 448 alsocomprises a rod 426 joined to the chassis 310 by its outside end andwhose inside end comprises a control piston 56 which extends into thecontrol chamber 451 to form with it the first control cylinder 445. Inits mid-section, said rod 426 also comprises the operating piston 52that extends into the operating chamber 50 to form with it the operatingcylinder 309.

The second control cylinder 446 is connected between the harvestingmechanism 411 and the gearbox 219. Positioning the gearbox 219 into theappropriate operating position is accomplished in the following manner.

To move from the mowing position on the left of the tractor (FIG. 10) tothe mowing position on the right (FIG. 11), one shortens the operatingcylinder 309 by injecting fluid via the conduit 53 to cause the drawbar5 to pivot in the direction 39 around the geometric axis 7 from workingposition 5G into working position 5D. In so doing, the inside end of therod 426 and the control piston 56 plunge more and more deeply into thecontrol chamber 451. The control piston 56 then expels the fluid intothe second control cylinder 446 through the conduit 47. In parallelfashion, fluid contained in the second control cylinder 446 is pumpedinto the first control cylinder 445 via the conduit 55. As a result, thesecond control cylinder 446 extends and causes the gearbox 219 to pivotin the same direction 39 around the geometric axis 23.

To move from the mowing position on the right of the tractor (FIG. 11)to the mowing position on the left (FIG. 10), one extends the operatingcylinder 309 by injecting fluid via the conduit 54 in order to cause thedrawbar 5 to pivot in the direction 40 around the geometric axis 7 fromworking position 5D into working position 5G. In so doing, the insideend of the rod 426 and the control piston 56 withdraw progressively fromthe control chamber 451. The control piston 56 then expels fluid intothe second control cylinder 446 through the conduit 55. In parallelfashion, fluid contained in the second control cylinder 446 is pumpedinto the first control cylinder 445 via the conduit 47. As a result, thesecond control cylinder 446 shortens and causes the gearbox 219 to pivotin the same direction 40 around the geometric axis 23.

A stop device 38 can be provided in all the embodiments that have justbeen described Said stop device 38 may, moreover, be embodied as aflexible stop such as a rubber stop, for example.

Various modifications remain possible without departing from theprotective scope delimited by the claims Thus one can modify theconstitution of the various elements described. One can also replacethese various elements with technical equivalents Finally, one can makeall the kinematic inversions technically possible.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:
 1. An agricultural machine comprising:a bodyequipped with at least one working component; a connecting mechanismallowing connection of said agricultural machine to a tractor vehicle,said connecting mechanism being connected to said body via a first jointwith an upwardly directed axis; an operating device for pivoting theconnecting mechanism with respect to said body around the axis of saidfirst joint, said connecting mechanism being positionable in at leasttwo working positions; transmission elements for powering said at leastone working component, said transmission elements including at least onegearbox connected to the body by a second joint with an upwardlydirected axis; and a control mechanism for pivoting said gearbox withrespect to said body around the second axis of said second joint, saidgearbox being positionable in operating positions corresponding to saidworking positions of the connecting mechanism; wherein said operatingdevices comprises:a first control cylinder positioned between theconnecting mechanism and the body; and wherein said control mechanismcomprises:a second control cylinder positioned between the body and thegearbox and connected in series with the first control cylinder.
 2. Anagricultural machine in accordance with claim 1 wherein:the firstcontrol cylinder and the second control cylinder are of thesingle-effect type, said second control cylinder controlling thepivoting of the gearbox in a first direction; and the control mechanismadditionally comprises a flexible control component installed betweenthe body and the gearbox and controlling the pivoting of said gearbox ina second direction.
 3. An agricultural machine in accordance with claim2 wherein a reaction generated by the driving torque applied to thegearbox tends to cause the gearbox to pivot in the second direction. 4.An agricultural machine in accordance with claim 1 wherein the firstcontrol cylinder and the second control cylinder are of the dual-actiontype and are connected in a closed circuit.
 5. An agricultural machinein accordance with claim 1 wherein the operating device comprises anoperating cylinder positioned between the connecting mechanism and thebody.
 6. An agricultural machine in accordance with claim 5 wherein:thefirst control cylinder and the second control cylinder are of thesingle-action type, said second control cylinder controlling thepivoting of the gearbox in a first direction; the control mechanismadditionally comprises a flexible control component installed betweenthe body and the gearbox that controls pivoting of said gearbox in asecond direction; the operating cylinder and the first control cylinderform a unit positioned between the connecting mechanism and the body;said unit comprises a cylinder body equipped with an operating chamberand a control chamber, and a rod equipped with an operating piston thatextends into the operating chamber so as to form with said operatingchamber the operating cylinder and wherein said rod extends into thecontrol chamber to form with said control chamber the first controlcylinder.
 7. An agricultural machine in accordance with claim 5wherein:the first control cylinder and the second control cylinder areof the dual-action type and are connected in a closed circuit; theoperating cylinder and the first control cylinder form a unit positionedbetween the connecting mechanism and the body; said unit comprising acylinder body equipped with an operating chamber and a control chamber,and a rod equipped with an operating piston extending into the operatingchamber so as to form with it the operating cylinder, said rodcomprising additionally a control piston which extends into the controlchamber to form with it the first control cylinder.
 8. An agriculturalmachine in accordance with claim 5 wherein the operating cylinder is ofthe dual-action type.
 9. An agricultural machine in accordance withclaim 1 wherein the gearbox is positionable in two operating positions,each of which is defined by a respective stop installed on the body. 10.An agricultural machine in accordance with claim 1 wherein thetransmission elements comprise at least one telescopic transmissionshaft with universal joints connected to the input shaft of the gearbox.11. An agricultural machine in accordance with claim 10 wherein said onetransmission shaft or at least one of said transmission shafts issupported by the connecting mechanism.
 12. An agricultural machine inaccordance with claim 1 wherein the transmission elements receivemovement of the power take-off shaft of the tractor to which the machineis connected.
 13. An agricultural machine in accordance with claim 1wherein:the body is supported on the ground by means of at least onewheel; and the connecting mechanism comprises a drawbar connected to themiddle section of said body.
 14. An agricultural machine in accordancewith claim 1 wherein the body comprises a chassis to which theconnecting mechanism is connected and in which the at least one workingcomponent is suspended by means of a suspension device so as to bemoveable with respect to the chassis in order to adapt to the groundterrain.